Inslated heating and/or sanitation pipe

ABSTRACT

The heating and/or sanitation pipe comprises an inner pipe ( 12 ) made of a plastic material and a metal corrugated pipe ( 14 ) surrounding the inner pipe ( 12 ) at a radial distance®). Further, the heating and/or sanitation pipe is provided with a compressible and/or expanded material ( 16 ) between the inner pipe ( 12 ) and the corrugated pipe ( 14 ) for fixing the inner pipe ( 12 ) inside the corrugated pipe ( 14 ). The compressible and/or expanded material ( 16 ) is adapted to be detached from the inner pipe for the purpose of exposing a connecting end of the inner pipe ( 12 ). Further, the heating and/or sanitation pipe comprises an insulation layer ( 18 ) surrounding the metal corrugated pipe ( 14 ) and an outer covering ( 20 ) around the insulation layer ( 18 ).

BACKGROUND OF THE INVENTION

[0001] The invention relates to a heat-insulated fluid-carrying, and inparticular water-carrying pipe which is in particular used in theheating and/or sanitation sector.

[0002] Heating pipes require a diffusion barrier which prevents oxygenfrom penetrating the pipe wall from outside. When the fluid-carryingpipe is made of plastic material, it is provided with a diffusionbarrier layer e.g. of EVOH. Alternatively, the plastic pipe can also becovered with a metal layer made in particular of aluminium. Bothmanufacturing processes necessitate special production steps which maybe rather complex.

[0003] Such a pipe is surrounded by a heat insulation material, e.g. aPE or PUR foam, for insulation purposes, wherein said insulation layeris surrounded by an outer plastic covering which in most cases isconfigured as a corrugated pipe.

SUMMARY OF THE INVENTION

[0004] It is an object of the invention to provide an insulated heatingand/or sanitation pipe comprising an inner pipe construction for themanufacture of which standard pipe components can be used.

[0005] According to the invention, an insulated heating and/orsanitation pipe is proposed which comprises:

[0006] an inner pipe of plastic material,

[0007] a metal corrugated pipe surrounding the inner pipe at a radialdistance,

[0008] a compressible and/or expanded material between the inner pipeand the corrugated pipe for fixing the inner pipe inside the corrugatedpipe,

[0009] wherein the compressible and/or expanded material is adapted tobe detached from the inner pipe for the purpose of exposing theconnecting end of said inner pipe,

[0010] an insulating layer surrounding the metal corrugated pipe, and

[0011] an outer covering around the insulating layer.

[0012] According to the invention, the heating and/or sanitation pipecomprises an inner pipe of plastic material which may be e.g. oxygen-or, more generally spoken, gas-permeable, but this is not absolutelynecessary. At a radial distance to the inner pipe the latter issurrounded by a metal corrugated pipe. For fixing the inner pipe insidethe metal corrugated pipe the gap between the two pipes is filled with acompressible and/or expanded material. This material is adapted to bedetached from the plastic material of the inner pipe for the purpose ofexposing the connecting end of said inner pipe, the detaching processbeing carried out in a simple manner and in particular manually suchthat the compressible and/or expanded material at the connecting end ofthe inner pipe can be removed e.g. by producing a radial circumferentialcut. Thus, a commercial fitting, e.g. a press fitting, can be connectedto the exposed connecting end of the inner pipe.

[0013] Around the inner pipe construction described above of theinventive insulated pipe a layer of heat insulating material (PE or PURfoam) is arranged which is surrounded by an outer covering in the formof e.g. a plastic corrugated pipe.

[0014] The invention offers the advantage that owing to provision of themetal corrugated pipe the inner pipe construction is oxygen- and watervapor-tight such that no moisture can enter the insulation layer. Due tothe flexibility of the overall pipe offered by the metal corrugatedpipe, the pipe is easy to lay as well as to coil and uncoil.

[0015] The inventive pipe construction counteracts any longitudinalexpansion of the inner pipe since the latter is supported by the outerpipe via the material arranged between the inner pipe and the outerpipe. Thus, the longitudinal expansion of the overall pipe is determinedby the longitudinal expansion of the metal outer pipe.

[0016] Further, the inventive pipe simplifies pipe installation sincethe metal outer (corrugated) pipe allows for plastic deformation of theoverall pipe.

[0017] The compressible and/or expanded elastic flexible material is inparticular a foam material. Generally, the expanded material is, in itsnon-expanded condition, deposited e.g. by extrusion on the plastic innerpipe, and is then expanded e.g. by heat after arrangement of the metalcorrugated pipe around the inner pipe.

[0018] The permeation-tightness of the inventive heating and/orsanitation pipe is achieved by provision of the metal corrugated pipe,and it is of no importance whether the plastic inner pipe isgas-impermeable. The manufacture of the metal corrugated pipe is a usualand established process. The metal corrugated pipe can be longitudinallyor helically welded, or the corrugated pipe structure is realized byforming a (smooth) metal pipe which is subsequently deformed into acorrugated pipe. As a medium-carrying inner pipe a pipe of a plasticmaterial which is normally used for pipe applications, e.g. PP or PE,can be used within the framework of the invention.

BRIEF DESCRIPTION OF THE DRAWING

[0019] Hereunder the invention is described in detail with reference tothe drawing which shows a perspective sectional view of an inventiveheating and/or sanitation pipe.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The heating and/or sanitation pipe 10 comprises an inner pipe 12made of plastic material, in particular a cross-linked plastic material,said inner pipe 12 being surrounded at a radial distance r by acorrugated pipe 14 made of metal, in particular aluminium. For fixingthe inner pipe 12 inside the corrugated pipe 14, a compressible and/orexpanded foam material 16 is used which fills the gap defined by theradial distance r. The foam material 16 is adapted to be detached in asimple and in particular residue-free manner from the inner pipe for thepurpose of exposing an inner pipe 12 connecting end designed to beconnected e.g. to a fitting. The foam material 16 fixes the inner pipe12 inside the corrugated pipe 14. The corrugated pipe 14 serves as awater vapor- and/or oxygen barrier (the latter in particular when theplastic inner pipe 12 does not comprise any oxygen diffusions barriere.g. of EVOH) and imparts the necessary permeation-tightness to theoverall pipe 10.

[0021] The inner pipe construction described above is surrounded by aheat insulation layer 18 around which a plastic outer covering 20configured as a corrugated pipe is arranged. The vapor barrier formed bythe metallic material of the corrugated pipe 14 prevents moisture fromentering the heat insulation layer 18 via the inner pipe 12, whereby thepipe 10 retains its insulation properties over its entire service life.

1. Heating and/or sanitation pipe comprising: an inner pipe (12) ofplastic material, a metal corrugated pipe (14) surrounding the innerpipe (12) at a radial distance (r), a compressible material (16) betweenthe inner pipe (12) and the corrugated pipe (14) for fixing the innerpipe (12) inside the corrugated pipe (14), wherein the compressiblematerial (16) is adapted to be detached from the inner pipe for thepurpose of exposing the connecting end of said inner pipe (12), aninsulating layer (18) surrounding the metal corrugated pipe (14), and anouter covering (20) around the insulating layer (18).
 2. Heating and/orsanitation pipe according to claim 1, characterized in that thecompressible material (16) is a foam material or a soft elastomericmaterial.
 3. Heating and/or sanitation pipe comprising: an inner pipe(12) of plastic material which is gas-impermeable, a metal corrugatedpipe (14) surrounding the inner pipe (12) at a radial distance (r), anexpanded material (16) between the inner pipe (12) and the corrugatedpipe (14) for fixing the inner pipe (12) inside the corrugated pipe(14), wherein the expanded material (16) is adapted to be detached fromthe inner pipe for the purpose of exposing the connecting end of saidinner pipe (12), an insulating layer (18) surrounding the metalcorrugated pipe (14), and an outer covering (20) around the insulatinglayer (18).
 4. Heating and/or sanitation pipe according to claim 3,characterized in that the expanded material (16) is a foam material. 5.Heating and/or sanitation pipe according to claim 1, characterized inthat the outer covering (20) is made of a plastic material.
 6. Heatingand/or sanitation pipe according to claim 1, characterized in that theouter covering (20) is configured as a corrugated pipe.